Sheet transfer gripper mechanism



' A. G/JACOBSON SHEET TRANSFER GRIPPER MECHANISM June 21, 1949.

2 Sheets-Sheet 1 Filed March 29, 1946 uvmvrox YflZ zar G Jacobaa/z, B

www 44,4 M $1 SHEET TRANSFER GRIPPER MECHANISM Filed March 29, 1946 2 Sheets-Sheet 2 -2 40 a 24-- 39 a A 2.11% I x O 47 49 45 50 I l,, l 0 I I r v 23 I 15 3 46 n5 C INVENTOR. dri/zurGJacobson BY tended motion thereby Arthur G. Jacobson, Chicago, .rIlL,

.assignor,

.mesne assignments, to The .Mieh le .sPrinting Press &

Manufac ing a corporation of Delaware Cesarean; Ghicasa; 1

Application March 29, 1Ql6, er ial;

dClain s. 1

In its broader aspectmyinvention relates to means whereby registeredsheets of material .are conveyed in succession to a sheet carryingmember of a printing press or other sheet handling machine.

More specifically,theinvention pertains to. an improvement in r nechanism generally known in the art as oscillatingstop gripperi. e. transfer gripper'mechanism and of the class such .asis described in the United States Letters Patent No. 1,790,457 issuedto Joseph R. Blaine January 27, 1931.

The improvement primarily consists in the simplification of such mechanism as is illustrated in said patent and to render it more particularly adaptable for handling sheets fed in lapped-sequence and at speed-greatly in excess of heretofore customary feeding speeds.

In their joint application for United States LettersPatent Serial No. 741,118,fi1ed -Apri1 12, 1947, now Patent No. 2,446,862 of April 12, 1949, Henri E. Peyrebrune and Bruno Pasquinelli have disclosed a novel step in the method of transferring to aprinting press or the like mechanism sheets which are fed and registered inlapped relation and by iwhichstepv it is possible .to 'make available all of the time that can be gained during thesheet transferring period. for the purpose of prolonging the time within which the sheets are to be registered.

In order to carry .said improved method into effect, it is required. tov provide novel. means applied to the gripper motion of the oscillating transfer grippers and therefore theprimary .object of my invention resides in the provision of simple and eflicient mechanism whereby the fundamental principles of said improvedmet'hod can be realized.

A further object of my invention is to provide an improved sheet transfer gripper mechanism wherein the gripper fingers and their associated gripper pads are mounted to rock about the same pivotal axis.

Another object of the invention consists in providing means whereby the sheet gripping elements after having engaged a registered sheet shall be positively locked against any uninassuring-that accurate registering position of the sheet shallbe' maintained.

Still further objects and advantages gained by my invention will be made apparent to' anyone skilled in the art from the following description and appended claims.

In order to exemplify the principle of my inven- -.tion,- I have illustrated. tone preferre accompanying v;d-rawi-ngs',..in which:

.xli'iigure leis yarf ragmentaryn sectional elevation of; tha improved-.gripper .mechanism showing; the sheet gripper; fingerseand:associatedjpads iclosed vocnraregistemdsheet; Figure.;2. in asimilar view. rdepictsithe .gripper elements in their .reeededsppsition .aiterya sheet :been' :transferredsby them tosgrippersof .an impression agylinder or 5 the ;,.like jsheet .ncarrying member; and

l ligiur'e :3 illustratesthe. positions assumed by thegri ppersand assnciatedipads. as they return to .grasp. arsucoeedingisheet.

LhauenotflhustratedEanyspecific meanswhere- ..:by.therstophgrtpperamechanism which embodies my inventionmayioeiactuated;however; it; will; be 'understood:thatqany well-known type of such .means can be utilizedafor. that purpose. .I make .particular referencegto, the operating vmechanism :disclosed .;in my iGfilZllBI United States Letters Patent'No. 1;77164 ,l04 issued June17, 1930.

sReierringnbwto.Figure. 1 of. the drawings, it willbe seen that.,;a.sequence. of lapped sheetsA, .Btand Cflaresupported on the registeringtable 1:0, Thesheet iA 'bearsagainst the front guides -l lewhiohsare mounted on ztherockjshaft .12 to .moveinto andoutof. their. operative i. e. registering.positionsin';'the.x:direction indicated by the .arrow N. .L'Ihegripper. fingers 5M and cooperating pads. Ir5 have closed on the leading edge of the Tregistered-isheet Aland are about to withdraw the sheet frbm tl'ie. table =l-i0..-a,=nd transfer it to the im- Jpression cylinder or the like sheet carrying mem- {aber 1:6 upon actuation ofthe transfer gripper operating -m0hal-1 i-S1'l'l, not {shownb'arid whereby cLform .inthe "Io thisshaft s'e"' r.ed a bracket 20 preferably by means-pr ci mpiagusvitels and a Woodru-if keyl9 and t'h bracket' carrie's the transfer gri pe l 4 pads'jl 5 and their associated operating me h; sm. iarfa'eimt go is al o formed with er tiir egiste seou red a 4 n jw-hi ce fin -transfer jgripper se secured to the shaft 23 is free end of which is pivoted perating rod 25 by means'of a PiYP Pi o stu ..Whis= l o arr a cam r ll FTP-Q M 1 .Partb .9 3 d... 'behind' 'the bracket j imi nb g gnl n h a lusts-preview on 55 etia 1-,iaa; The rod 25 extends throu the bracket and is urged upward by means of an expansion spring 29 which embraces the rod and which is placed between the lug 28, bearing against a washer 30 and a washer 3| adjustably positioned by means of a nut 32 threaded onto the free end of the rod 25.

Accordingly the action of the spring 29 will tend to move the gripper shaft 23 and therewith the fingers M in an anticlockwise direction as viewed in Figure 1 and also maintain the roller 21 in contact with the cam 33. This cam is mounted on the driving gear shaft, not shown, of the transfer gripper mechanism, rotates continuously in the direction indicated by the arrow and has such a contour that the operating and closing motion of the gripper fingers I4 is controlled thereby.

The gripper pads l5, corresponding in number with that of the series of fingers l4 carried by the shaft 23, are secured in any approved manner to a gripper pad bar 35 carried by an arm 36 and extending across the entire width of the registering table In. Said gripper pad bar 35 having slots or notches, not shown, provided at appropriate locations to assume clearance for the arm 22 of bracket 20 when the arms 33 and thereby the pads l5 are withdrawn to the position shown in Figure 2. The arm 36 is mounted to pivot about the axis of the gripper shaft 23 and carries a cam roller 31 which is urged against a cam 38 by means of an expansion spring 39 through the intermediary of operating rod 40, pivoted to the free end of the arm 36. This rod extends through a lug 4| also provided in the bracket 20 and is urged upwards by the spring 39 which, similarly to the spring 29 of the rod 25, is held in position on the free end of the rod 40 by means of a washer 42 and nut 43 threaded onto the rod.

The novel arrangement of mounting the gripper fingers l4 and associated pads l5 so as to rock about the same pivotal axis provides the basis for a much simpler and more efiicient operating stop gripper mechanism than any heretofore known, that is in which the fingers and pads are moved about separate pivotal axes.

In order to positively lock the gripper pads l5 and therewith the fingers 14 against any unintended motion and to take up any undesirable play between the cooperating elements, I propose to provide some means whereby the roller 31 shall be held in intimate contact with the cam 38. This cam, like the cam 33, rotates continuously in the direction indicated by the arrow and is mounted on the driving gear shaft of the transfer gripper mechanism and its contour is such as to control the movement of the gripper pads and the receding motion of the pads as well as of the gripper finger it.

According to the preferred arrangement shown, I provide a locking bar 45 which is formed with a machined face 65 adapted to bear against a machined curved face 41 provided on the arm 36. This locking bar is attached to a suitable part of the press frame and is formed with elongated slots 48 to accommodate locking screws or the like 49 and 50. If any clearance develops between the machined faces 46 and 41, it can be readily taken up by loosening said set screws, readjusting the locking bar 45 so that its face 45 will again bear firmly against the cooperating curved face 41, and again tightening the set screws.

It will be understood that the locking bar 45 could be urged resiliently against the arm 36 in order to maintain intimate contact between the machined faces 46 and 41.

In order to simplify the showing of the gripper elements and associated operating mechanism in Figure 2 I have indicated the bracket 28 in broken lines.

The operation of the mechanism thus described is as follows:

Referring first to Figure 1, the sheet A is about to be withdrawn from the registering table 10 and the withdrawal commences at an accelerating speed as soon as the front guides U have moved down and away from the edge of the registered sheet A. By the time the transfer grippers have reached the position indicated by the broken lines in Figure 2, the front guides ll have again moved up to register the next lapped sheet B. Upon transferring of the sheet A to the grippers 5| of the sheet carrying member 16, the roller 31 begins to ride over the low portion of the cam 38 and likewise the roller 21 commences to ride over the low portion of the cam 33, resulting in the receding of the fingers and pads from their plane of transfer operation which is indicated as DD in Figure 1. Immediately thereafter the fingers and pads are returned to their sheet gripping position and by virtue of the contours of cams 33 and 38, these elements remain receded until the trailing edge of the sheet A has just passed over the front guides H and to a sufficient degree beyond them to permit the gripper fingers Hi to drop into the provided gap as shown in Figure 3, i. e. simultaneously with the passing of the trailing edge of the withdrawn sheet A over and beyond said guides, and then move up to close on the now registered sheet B the arm 36 remaining in its receded position until completion of the return stroke, whereupon the arm 36 is depressed until the pads l5 rest in position on sheet B, simultaneously locking the unit against the bar 45 to hold the gripper fingers M and pads l5 against any unintended motion. As the pads move down in position, the fingers 14 close on said pads, gripping the sheet therebetween. In the meantime the lapped sheet C will have advanced to the position assumed by the sheet B as shown in Figure 1.

While I have chosen to illustrate and describe a preferred form of my improved transfer mechanism and associated parts, it will be readily understood that the arrangement can be subject to constructional changes without departing from the principle of the invention and therefore I intend to cover any such mechanical modifications that will come within the terms of the appended claims.

I claim:

1. In sheet feeding mechanism of the class set forth, the combination comprising a support for sheets, sheet registering means, mechanism for transferring individual, registered sheets to a sheet carrying member, gripper fingers and cooperating pads carried by said mechanism, said fingers and pads being mounted for independent movement about a common axis, means for withdrawing said fingers and pads from their plane of transfer operation after a sheet to be transferred has been released by them, and means to return said fingers and pads to their sheet engaging position.

2. In sheet feeding mechanism of the class set forth, the combination comprising a support for sheets fed in lapped sequence, means for registering sheets while lapped, mechanism for transferring individual, registered sheets to a sheet carrying member, gripper fingers and cooperating pads carried by said mechanism, said fingers and pads being mounted for independent movement about a common axis, means for withdrawing said fingers and pads from their plane of transfer operation after a sheet to be transferred has been released by them, and means to return said fingers and pads to their sheet engaging position while withdrawn.

3. In sheet feeding mechanism of the class comprising a, support for sheets, sheet registering means, and mechanism for transferring individual, registered sheets to a sheet carrying member, the provision of sheet gripping elements carried by said mechanism and including gripper fingers and associated pads mounted for independent movement about a common axis, means for withdrawing said elements from their plane of transfer operation after a sheet to be transferred has been released by them, means to return said elements to their sheet engaging position, and means for positively locking said elements against any unintended circumferential movement While closing on a registered sheet.

4. In sheet feeding mechanism of the class comprising a support for sheets fed in lapped sequence, means for registering sheets while lapped, and mechanism for transferring individual, registered sheets to a sheet carrying member, the provision of sheet gripping elements carried by said mechanism and including gripper fingers and associated pads mounted for independent movement about a common axis, means for withdrawing said elements from their plane of transfer operation after a sheet to be transferred has been released by them, means to return said elements to their sheet engaging position while withdrawn, and means for rigidly locking said elements against any unintended circumferential movement while closing on a registered lapped sheet.

5. In sheet feeding mechanism of the class comprising a support for sheets, sheet registering means, and mechanism for transferring individual, registered sheets to a sheet carrying member, the provision of sheet gripping elements carried by said mechanism and including gripper fingers and associated pads mounted for independent movement about a common axis, means for withdrawing said elements from their plane of transfer operation after a sheet to be transferred has been released by them, means to return said elements to their sheet engaging position, and adjustable means for rigidly locking said elements against any unintended circumferential motion while closing on a registered sheet.

6. In a sheet transfer mechanism for conveying sheet material in lapped sequence from a support to a, sheet carrying member, the cornbination of a drive shaft, brackets fixed on said shaft, a gripper shaft supported by said brackets, gripper fingers and gripper pads supporting means mounted coaxially on said gripper shaft, sheet registering guides, means for actuating said gripper fingers and pads for engaging the foremost one of a bank of lapped sheets in order to transfer it to the sheet carrying member, means for receding said fingers and pads from the path followed by the transferred sheet to clear it, and means operative during the return movement of the gripper fingers to project them into and beyond said path simultaneously with the passing of the trailing edge of the withdrawn sheet over and beyond said registering guides.

ARTHUR G. JACOBSON.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date ll37,347 Cottrell Apr. 1, 1873 1,128,390 Upham Feb. 16, 1915 1,764,104 Jacobson June 17, 1930 1,790,457 Blaine Jan. 27, 1931 2,092,189 Stobb Sept. 7, 1937 2,192,908 Harrold et a1 Mar. 12, 1940 2,192,916 Kaddeland et al. Mar. 12, 1940 

